Systems and methods of control for plasma processing

A method of plasma processing comprising:

• outputting a first signal from a source power (SP) control path to a timing circuit;
• generating a first SP pulse according to SP pulse parameters and the first signal using the SP control path;
• triggering a delay using the timing circuit in response to detecting a leading edge of the first signal or a trailing edge of the first signal, the leading edge of the first signal corresponding with a leading edge of the first SP pulse and the trailing edge of the first signal corresponding with a trailing edge of the first SP pulse, the delay causing a first nonzero offset duration between the trailing edge of the first SP pulse and the leading edge of a bias power (BP) pulse;
• generating a trigger signal immediately following the first nonzero offset duration using the timing circuit;
• outputting the trigger signal from the timing circuit to a BP control path;
• generating the BP pulse triggered by the trigger signal using the BP control path, the BP pulse being generated according to BP pulse parameters separate from the SP pulse parameters;
• generating a plasma in a plasma processing chamber using the first SP pulse;
• and
• coupling the BP pulse to a substrate disposed in the plasma processing chamber.

A plasma processing apparatus comprising:

• a plasma processing chamber;
• a source power (SP) control path comprising an SP pulse modulation circuit configured to generate a first signal,
• an SP function generator configured to generate SP pulses according to the first signal and SP pulse parameters, and
• an SP coupling electrode configured to generate a plasma in the plasma processing chamber using the SP pulses;
• a timing circuit coupled to the SP pulse modulation circuit and configured to
• generate a delay causing a first nonzero offset duration separating trailing edges of the SP pulses and leading edges of bias power (BP) pulses, and
• output a trigger signal immediately following the first nonzero offset duration;
• and
• a BP control path comprising
• a BP pulse modulation circuit coupled to the timing circuit and configured to generate a second signal triggered by the trigger signal,
• a BP function generator configured to generate BP pulses according to the second signal and BP pulse parameters separate from the SP pulse parameters, and
• a substrate holder configured to support a substrate disposed in the plasma processing chamber and to accelerate ions from the plasma towards the substrate using the BP pulses.